Integ (1)A-1

Chapter 7: Integumentary System

Learning Outcomes

  • Describe the integumentary system and its accessory structures.

  • List functions of the skin.

  • Explain common integumentary diseases, diagnostic procedures, and drug categories.

Dermatology

  • Specialty studying the anatomy and physiology of the integumentary system.

  • Uses diagnostic tests, medical procedures, and drugs for treatment.

Anatomy and Physiology Overview

  • Composed of the skin, hair, nails, sebaceous glands, and sweat glands.

  • Largest organ of the body.

Five Basic Functions of Skin

  1. Protection

  2. Regulation

  3. Sensory Reception

  4. Elimination (Secretion)

  5. Synthesis of Vitamin D

Functions of the Skin

  • Protection: Shields against bacteria, mechanical injury, prevent dehydration, and blocks UV radiation.

  • Regulation: Maintains body temperature through blood vessel dilation and sweating.

  • Sensation: Contains nerve endings for pain, touch, heat, cold, and pressure.

  • Secretion: Produces sweat and oil for skin lubrication.

  • Synthesis: Begins Vitamin D production using UV light.

Structures of the Skin

1. Epidermis

  • Outermost layer, thinnest at eyelids and thickest at palms/soles.

  • Composed of 5 layers of epithelial cells.

  • Contains melanocytes in the stratum basale which produce melanin.

2. Dermis

  • Below epidermis composed of connective tissue with collagen and elastin fibers.

  • Contains blood vessels, nerve cells, hair follicles, sebaceous glands, and sweat glands.

3. Subcutaneous Layer

  • Below dermis, provides insulation and cushions.

Accessory Structures

  • Hair: Formed in hair follicles, influenced by melanocytes for color.

  • Nails: Protect distal ends of fingers/toes.

  • Glands: Sweat glands regulate temperature; sebaceous glands secrete sebum.

Common Integumentary Diseases and Conditions

  • Dermatitis: Inflammation of the skin; treatment includes correcting underlying causes.

  • Psoriasis: Autoimmune disorder causing red, scaly patches. No cure, but treatments include vitamin applications and phototherapy.

  • Skin Infections: Caused by bacteria or fungi leading to abscesses, boils, or cellulitis.

  • Skin Cancers: Basal cell carcinoma, squamous cell carcinoma, and malignant melanoma.

  • Acne Vulgaris: Inflammation of sebaceous follicles leading to lesions like papules and pustules.

Diagnostic Techniques, Treatments, and Procedures

  • Skin Biopsy: Sample taken for microscopic examination.

  • Cryosurgery: Freezing method to destroy tissue.

  • Debridement: Removing dead tissue.

  • Liposuction: Fat removal procedure.

  • Skin Grafting: Placing tissue to aid recovery in damaged areas.

Important Terms

  • Histamine: Release causes allergic reactions such as redness and swelling.

  • Anaphylaxis: Severe allergic reaction requiring immediate treatment.

  • Callus: Thickened skin due to pressure.

Conclusion

The integumentary system is crucial for protection, sensation, and regulation of body functions, with a variety of diseases and conditions affecting its health.